title: Self-seeded lasing in ionized air pumped by 800 nm femtosecond laser pulses.
abstract: We report on the lasing in air and pure nitrogen gas pumped by a single 800 nm femtosecond laser pulse. Depending on gas pressure, incident laser power and beam convergence, different lasing lines are observed in the forward direction with rapid change of their relative intensities. The lines are attributed to transitions between vibrational and rotational levels of the first negative band of the singly charged nitrogen molecule-ion. We show that self-seeding plays an important role in the observed intensity changes.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Yohann
authors.initials: Y
authors.lastname: Brelet
authors.forename: Guillaume
authors.initials: G
authors.lastname: Point
authors.forename: Aurélien
authors.initials: A
authors.lastname: Houard
authors.forename: André
authors.initials: A
authors.lastname: Mysyrowicz